Senate seat swaps a good bet

Here's a list of Democratic seats in play:

Arkansas: Sen. Blanche Lincoln fended off a primary challenge, but she faces a solid challenge to her re-election from Republican U.S. Rep. John Boozman.

California: Sen. Barbara Boxer, who's seeking her fourth term, is being tested by Republican Carly Fiorina, a former Hewlett-Packard CEO.

Colorado: Sen. Michael Bennet is seeking a full term after being appointed to the seat left vacant when Ken Salazar was named the secretary of the interior. He's facing conservative Republican Ken Buck, a local prosecutor and tea party favorite.

Delaware: Democrats wanted state Attorney General Beau Biden to run for the seat once held by his father, Vice President Joe Biden. With him sitting it out, Democrats nominated New Castle County Executive Chris Coons. He faces a tough race against Republican U.S. Rep. Michael Castle, if Castle survives the primary Sept. 14 against tea party challenger Christine O'Donnell as expected.

Illinois: Democratic state Treasurer Alexi Giannoulias is fighting to keep the seat that Barack Obama once held. He's being challenged by U.S. Rep. Mark Kirk, a centrist Republican.

Indiana: U.S. Rep. Brad Ellsworth is the Democratic candidate for the seat that's being vacated by retiring Sen. Evan Bayh. The Republican is former Sen. Dan Coats.

Nevada: Sen. Harry Reid, the Senate majority leader, is in danger of being defeated by Republican Sharron Angle, a tea party favorite.

North Dakota: The Democratic candidate is state Sen. Tracy Potter; the Republican is Gov. John Hoeven, the longest-serving governor in the state's history.

Pennsylvania: Pat Toomey, a former congressman, started running for this seat back in 2009. His early candidacy for the Republican nomination scared Republican Sen. Arlen Specter so much that the veteran senator changed parties, only to lose the Democratic primary. Toomey now faces the man who defeated Specter, U.S. Rep. Joe Sestak, a retired admiral with a Ph.D. from Harvard.

Washington: Sen. Patty Murray, the secretary of the Senate Democratic Conference, is seeking a fourth term against Republican Dino Rossi, a former state senator who's lost two governor campaigns.

Wisconsin: Sen. Russ Feingold, who co-authored the McCain-Feingold law limiting campaign money, is struggling to win a fourth term. He'll run against the winner of a Republican primary Sept. 14.

Republican seats in play:

Alaska: Sen. Lisa Murkowski was defeated in a primary, and Republican Joseph Miller, a tea party candidate, will face Democrat Scott McAdams, the mayor of Sitka.

Florida: A three-way race for the seat left vacant by the resignation of Republican Sen. Mel Martinez last year and the decision by appointed successor George LeMieux not to seek a full term. The Democrat is U.S. Rep. Kendrick Meek, the independent is Gov. Charlie Crist, a former Republican, and the Republican is former state House Speaker Marco Rubio.